You are Buying one Pair of Brand New 2 Adjustable Concealed Standard Spray Standard and Quick Response V3801 V3802 Product Description: This concealed, designer style sprinkler allows up to 1/2"/13 mm adjustment to accommodate concealment needs. The ?standard? design provides a consistent hemispherical spray pattern. The separate two-piece mounting cup/cover plate allows easy installation and testing prior to ceiling installation. It also permits removal of suspended ceiling panels without system shutdown. This sprinkler is available in various temperature ratings (see chart on page 3) and finishes to meet many design requirements. Technical Specifications: Models: V3801, V3802 Style: Adjustable concealed, ordinary hazard, light hazard Nominal Orifice Size: 1/2"/13 mm K-Factor: 5.6 Imp./8.1 S.I.1 Nominal Thread Size: 1/2"/15 mm Max. Working Pressure: 175 psi/1200 kPa Factory Hydrostatic Test: 100% @ 500 psi/3450 kPa Min. Operating Pressure: 7 psi/48 kPa